INDIRECT HYPERBILIRUBINEMIA

Dr Ira Shah

doi:https://10.7199/ped.oncall.2016.5

INDIRECT HYPERBILIRUBINEMIA

Dr Ira Shah.

Medical Sciences Department, Pediatric Oncall, Mumbai, India.

ADDRESS FOR CORRESPONDENCE
Dr Ira Shah, 1, B Saguna, 271, B St Francis Road, Vile Parle {W}, Mumbai 400056

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Clinical Problem
A 3 years old boy presented with persistent indirect jaundice since 1 month of life. At 4 months of age he was detected to have involuntary movements with developmental delay. MRI brain showed hypomyellination with hyper intensities in globus pallidus. He was investigated for indirect hyperbilirubinemia.
• G6PD – Normal
• Thyroid function tests – Normal
• Osmotic fragility – Normal
• Pyruvate kinase levels – Normal
• RBC membrane defect – Not detected
• Reticulocyte count – Normal

At 3 years, bilirubin = 12.4 mg, dl {11.4 mg, dl – indirect}.

What is the cause of indirect hyperbilirubinemia_?

Discussion
This child had kernicterus due to indirect hyperbilirubinemia. Since jaundice is still persisting it is unlikely to be due to ABO incompatibility or Rh incompatibility. Since all other causes of indirect hyperbilirubinemia have been ruled out, the most likely cause is Criggler Najjar syndrome {CNS}. This syndrome is divided into types I and II and is inherited in an autosomal recessive manner. Intense jaundice appears in the first days of life and persists thereafter. Type 1 is characterised by a serum bilirubin usually above 345 µmol, l {310–755} {whereas the reference range for total bilirubin is 2–14 µmol, l}. No UDP glucuronosyltransferase 1-A1 {UGT} expression can be detected in the liver tissue. Hence, there is no response to treatment with phenobarbitone. Liver transplant is the treatment of choice for type 1 CNS. Before transplantation the serum bilirubin level of CNS type 1 patients should be kept below 350 micromol, l with daily phototherapy. {1} If patients get kernicterus or have neurological impairment, then the neurological outcome is not good. In type-2, bilirubin is between 6 to 20 mg, dl and kernicterus is rare. UGT is reduced and treatment with phenobarbitone is effective. Although no simple, widely available clinical test is available to confirm the diagnosis of Crigler-Najjar syndrome, unconjugated hyperbilirubinemia in the presence of normal liver function test findings is characteristic of the disease. Diagnosis can be established by gene analysis or by liver biopsy demonstrating enzyme transferase activity.

Compliance with ethical standards

Funding: None

Conflict of Interest: None

References